Double-blind randomized clinical trial of posterior composite restorations with or without bevel: 6-month follow-up

This double-blind randomized clinical trial compared the performance of posterior composite restorations with and without bevel.

Thirteen volunteers requiring at least two posterior Class II restorations were selected. Twenty-nine cavity preparations were performed, comprising 14 without bevel (butt joint) and 15 with marginal beveling. All cavities were restored with a simplified adhesive system (Adper Single Bond, 3M ESPE, St. Paul, Minnesota, USA) and composite resin (Filtek P60, 3M ESPE, St. Paul, Minnesota, USA). A halogen light-curing unit (XL 3000, 3M ESPE, St. Paul, Minnesota, USA) was used throughout the study. Restorations were polished immediately. Analysis was carried out at baseline and after six months by a calibrated evaluator (kappa), according to FDI criteria.

The results were statistically analyzed by Kruskal-Wallis and Mann-Whitney tests (p<0.05). Beveled and nonbeveled restorations performed similarly after six months in relation to fractures and retention, marginal adaptation, postoperative hypersensitivity, recurrence of caries, surface luster, and anatomic form. However, for surface and marginal staining, beveled restorations showed significantly better performance than butt joint restorations (p<0.05).

Restorations performed were acceptable after six months, but beveled restorations showed less marginal staining than nonbeveled restorations.

Bevel used in posterior composite restorations decreased the surface and marginal staining, in six-month evaluations.